Magneto



NOV 4 1947- E. c. Kil-:KHAEFER 2,430,057

MAGNETD Filed Dec. 15, 1944 3 Sheets-Sheet 1 Nov. 4, 1947. E. c. KIEKHAEFER MAGNETO Filed DSC. l5, 1944 3 Sheets-Sheet 2V Nov. 4, 1947. E. c. KIEKHAEFER MAGNETO Filed DBC. 15, 1944 3 Sheets-Sheet 3 Patented Nov. 4, 1947 UNITED STATES PATENT oFFlcE MAGNETO Eimer Q. Kiekhaefer, Cedarburg, Wis. Application December 15, 1944, Serial No. 568,341

, 7 Claims.

This invention relates to an improvement in a magneto of the kind equipped with an impulse starter.

The object of the invention is to improve, simplify, and compact a magneto of this character and to do this in such a way that substantial advantages are realized not only in manufacturing, but also in use. I'he structure is easy and compartively inexpensive to manufact-ure. In operation it is reliable and highly efilcient.

Generally speaking, these objectsand advantages are realized by so constituting and so organizing the magneto that the rotor thereof is directly and rotatably supported on the crank shaft of the engine and this by its own bearings, the crank shaft extendingthrough the center of the rotor of the magneto. A spring operatively interconnects the crank shaft and the magnet rotor and serves the dual purpose of applying the force required to flip thev magnet rotor through a generating cycle when the engine is cranked and of transmitting torque from the crank shaft to the magnet rotor when the engine is running normally.

These objects of the invention and other ancillary advantages are attained by the mechanism, construction, and arrangement illustrated in the accompanying drawings forming part hereof, in which:

Fig. 1 is a fragmentary view in vertical cross section taken on line I--I of Figure 2, parts being shown in elevation for the sake of illustration; and

Figures 2,' 3 and 4 are fragmentary views in horizontal cross section taken respectively on lines 2--2, 3-3 and 4-4 of Figure 1, with parts ,shown in elevation for the sake of illustration;

Fig 5 is a view similar to Figure 1 but showing the holding pin which co-acts with the pawl attached to the crank case of the engine and extending through a slot in the mounting plate;

Fig. 6 is a fragmentary view taken on line 6-5 of Figure to further illustrate the slot of the mounting plate through which the holding pin extends; and v Fig. 7 is a view similar to Figure 5 but showing another modification of the invention and one wherein the mounting plate is rigidly attached to the crank case of the engine.

Referring to the drawings, the numeral 5 designates a portion of the crank case of an internal combustion engine.l The crank shaft 6 of the engine has an extension 1 projecting through a bearing 8 provided therefor on the crank case 5 vmagnet rotor I5 in cooperative relation to the laminated pole pieces I5 of the coil I I.

The rotor I5 is combined in a special and advantageous way with the extension 1 of the crank shaft 5. For this purpose a bearing sleeve I1 is inserted in the axial opening of the body of the rotor I5 and is secured thereto by a press fit or in any other suitable way. In the assembly, the bearing sleeve I1 is rotatably fitted on the extension 1 of the crank shaft 6. The crank shaft thus passes through the center of the magnet rotor I5 and the magnet rotor I5 is directly mounted on the crank shaft for rotation relative thereto and is so mounted by its own bearings. While a sleeve bearing Is a simple and advantageous bearing, of course. other wel1 known types of bearings may be employed.

A cup I8 is fixed to the upper end of the bearing sleeve I1. A helical spring I9 of the clock spring type is accommodated in the cup I8 and has its inner end fixed to the crank shaft and its outer end fixed to the cup I8 and consequently is fixed also to the rotor I5.

The lower end of the bearing sleeve I1 has a flange 20 fixed thereto. A pawl or dog 2| is pivotally supported as at 22 on the flange 20 and is cooperable with an abutment or holding pin 23 in certain phases of the operation.

A fly wheel 25 is secured at 2B to the upper or outer end of the extension 1 of the crank shaft B.

With this construction, when the fly wheel 25 is spun to crank the engine, the rotor l5 of the magneto remains stationary due to the interengagement of the pawl 2i with the abutment or holding pin 23 as shown in Figure 4, but this only for a part of the revolution, for as the crank shaft turns, a flat 21 thereon engages a camming surface 28 on the pawl 2| to swing the pawl about the pivot 22 to disengage it from the pin 23. During the interval that the rotor i5 has remained stationary, the spring I9 is wound up so that u pon disengagement of the pawl 2| from the pin 23, the spring I9 will flip the magnet rotor 3 i rapidly through a part of arevolution thereby generating a good spark. As the engine comes up to speed, the weighted end 29 of the pawl 2| responding to centrifugal force will maintain the pawl 2| inwardly oi' the pin 23 and consequently prevent its engagement therewith.

The weighted end 23 of pawl 2| is constructed to engage pin 23 and move the pawl outwardly to engaging position each time the weighted end 29 passes between the pin 23 and shaft 1. As soon as the weighted end 29 passes the pin 23 and is free thereof, it swings outwardly under centrifugal force and moves pawl 2| inwardly in time for the latter to pass freely between pin 23 and shaft 1.

When the engine stops, slow rotation of the rotor causes the outer cam surface of end 29 to engage pin 23 and-force pawl 2| outwardly to operative position while-the speed of rotation is insumcient to swing the end 29 outwardly as it leaves pin 23. The pawl 2| is thereby automatically re-set to engage pin 23 upon the next cranking of the engine.

In cranking the engine, the pawl 2| engages pin 23 and effects compression of spring i9 and a delayed action in the drive between shaft 1 and rotor I5. The pawl is finally released by the cam action between the surface 21 on shaft 1 and the inner cam surface 28 on end 29.

In other words the parts are so designed and inter-related that the moment the piston (not shown) of the engine reaches firing position the pawl 2| is disengaged from the pin 23 and the spring |9 flips the magnet rotor through a generating cycle with sufiicient speed to produce ignition current for one firing. I'hls operation will continue as long as the engine is cranked, when the engine fires and starts to run normally, the magnet rotor I5 is driven from the crank shaft through the spring i9.

As illustrated in Figures 1 and 5 a handle 35 may be attached by screws to the mounting plate 9. In the construction illustrated in Figure 1 the handle when grasped and pulled in one direction or the other shifts the mounting plate 9 to advance or retard the spark in as much as the coil interrupter I2, and condenser I3 are rigidly fixed to the mounting plate and turned therewith. The same action in respect to ignitions occurs upon manipulation of the handle 35 in Figure 5, with this exception. When the mounting plate of the construction shown in Figure 1 is retarded by manipulation of its handle 35, the relative position of the pawl 2| with respect to the holding pin is varied. In some instances itis desirable to avoid such a variation and with this in mind the construction shown in Figures 5 and 6 is proposed. In this instance the holding pin designated at 31 in Figures 5 and 6 is screwed into an internally threaded opening in the crank case of the engine and extends through a slot provided in the mounting plate 9. Obviously, adjustment of the mounting plate 9 in the construction shown in Figures 5 and 6 while advancing or retarding the spark will not disturb the predetermined or selected relationship between the holding pin 31 and its cooperative pawl 4|.

Fig. 7 shows still a further modification of the invention in that the mounting plate 9 is rigidly attached by a suitable number of screws 43 to the crank case of the engine in such angular relation that the holding pin 23 and its cooperative pawl 2| are in proper operative relation.

While I have shown and described several constructions in which the invention may be ad- 4 vantageously'embodied. it is to be understood that the constructions shown have been selected merely for the purpose of illustration or example, and that various changes in the size. shape, and

5 arrangement of the parts may be made without departing from the spirit of the invention or the scope of the subioined claims.

What I claim is:

1. A magneto of the class described adapted to be mounted adjacent an engine crank case with the engine shaft passing axially therethrough, comprising a substantially stationary coil having a core with spaced pole pieces disposed on opposite sides of the shaft, a magnet rotor mounted on said shaft for rotation therewith between said pole pieces to energize said coil for providing ignition current to the engine. a cushion drive between said rotor and shaft having energy storing means adapted to provide a quick forward kick to the rotor during starting, means locking said rotor against turning with said shaft when cranking the engine to elect delayed action of said drive and storage of energy thereby, means to trip and release said locking means in response to the rotation of the shaft, and means solely responsive to the rotation of the rotor for resetting said locking means.

2. A magneto of the class described adapted to be mounted adjacent an engine crank case with the engine shaft passing axially therethrough, comprising a substantially stationary coil having a. core with spaced pole pieces disposed on opposite sides of the shaft, a magnet rotor mounted on said shaft for rotation therewith between said pole pieces to energize said coil for providing ignition current to the engine, a cushion drive between said rotor and shaft having energy storing means adapted to provide a quick forward kick to the rotor during starting, means locking said rotor against turning with said shaft when cranking the engine to effect delayed action of said drive and storage of energy thereby, means to trip and release said locking means in response to the rotation of the shaft. means responsive to centrifugal forces resulting from the rotation of the shaft to prevent operation of said locking means during operation of the engine, and means responsive to the slow rotation of the rotor for resetting said locking means upon stopping of the engine.

3. A magneto of the class described adapted to be mounted adjacent an engine crank case with the engine shaft passing axially therethrough, comprising a substantially stationary coil having a core with spaced pole pieces disposed on opposite sides of the shaft, a magnet rotor mounted on said shaft for rotation therewith between said pole pieces to energize said coil for providing ignition current to the engine, a cushion drive between said rotor and shaft having energy storing means adapted to provide a quick forward kick to the rotor during starting, a locking pin disposed adjacent said rotor, a pawl pivotally carried by said rotor operable to engage said pin and lock said rotor against turning with said shaft when cranking the engine to effect delayed action of said drive and storage of energy thereby, means to trip said pawl in response to the rotation of the shaft to release the stored energy in said drive and provide the starting ignition for the engine, and a weighted arm on said pawl adapted to pivot the same in response to centrifugal forces to a position where the pawl clears the pin during operation of the engine, said arm on said pawl being disposed to engage said pin and re-set the pawl for locking said rotor upon stopping of the engine.

4. A magneto of the class described adapted to be mounted on an engine crank case with the engine shaft passing axially therethrough, comprising a mounting plate carried by the crank case, a stationary coil carried by the mounting plate, a magnet rotor mounted on the engine shaft for rotation therewith to energize said coil for providing ignition current to the engine, a cushion drive between said rotor and shaft and having energy storing means adapted to provide a quick forward kick to the rotor during starting, a, locking pin secured to said mounting plate adjacent the rotor, a pawl pivotally carried by said rotor operable to engage said pin and lock said rotor against turning with said shaft when cranking the engine to effect delayed action of said drive and storage of energy thereby, means to trip said pawl in response to the rotation of the shaft to release the stored energy in said drive and provide th starting ignition for the engine, and a weighted arm on said pawl adapted to pivot the same ln response to centrifugal forces to a position where the pawl clears the pin during operation of the engine, said arm on said pawl being disposed to engage said pin and re-set the pawl fci r locking said rotor upon stopping of the eng ne.

5. A magneto of the class described adapted to be mounted on an engine crank case with the engine shaft passing axially therethrough, comprising a mounting plate carried by the crank case, a stationary coil carried by the mounting plate, a magnet rotor mounted on the engine shaft for rotation therewith to energize said coil for providing ignition current to the engine, a cushion drive between said rotor and shaft and having energy storing means adapted to provide a quick forward kick to the rotor during starting, a locking pin secured to said mounting plate adjacent the rotor, a pawl pivotally carried by said rotor operable to engage said pin and lock said rotor against turning with said shaft when cranking the engine to effect delayed action of said drive and storage of energy thereby, means to trip said pawl in response to the rotation of the shaft to release the stored energy in said drive and provide the starting ignition for the engine, a weighted arm on said pawl adapted to pivot the same in response to centrifugal forces to a position where the pawl clears the pin during operation of the engine, said arm on said pawl being disposed to engage said pin and re-set the pawl for locking said rotor upon stopping of the engine, and means for adjustably rotating said mounting plate relative to the engine to effect adjustment in the timing of the ignition.

6. A magneto of the class described adapted to be mounted on an engine crank case with the engine shaft passing axially therethrough, comprising a mounting plate carried by the crank case, a stationary coil carried by the mounting plate, a magnet rotor mounted on the engine shaft for rotation therewith to energize said coil for providing ignition current to the engine, a cushion drive between said rotor and shaft and having energy storing means adapted to provide a quick forward kick to the rotor during starting, a locking pin secured to the crank case and exy tending through a slot in said mounting plate to a position adjacent the rotor, a pawl pivotally carried by said rotor operable to engage said pin and lock said rotor against turning with said shaft when cranking the engine to effect delayed action of said drive and storage of energy thereby, means to trip said pawl in response to the rotation of the shaft to release the stored energy in said drive and provide the starting ignition for the engine, a weighted arm on said pawl adapted to pivot the same in response to centrifugal forces to a position where the pawl clears the pin during operation of the engine, said arm on said pawl being disposed to engage said pin and re-set the pawl for locking said rotor upon stopping of the engine, and means for adjustably rotating said mounting plate relative to the engine to effect adjustment in the timing of the ignition.

7. A magneto of the class described adapted to be mounted on an engine crank case with the engine shaft passing axially therethrough, comprising a mounting plate carried by the crank case, a stationary coil carried by the mounting plate, a magnet rotor mounted on the engine shaft for rotation therewith to energize said coil for providing ignition current to the engine, a cushion drive between said rotor and shaft and having energy storing means adapted to provide a quick forward kick to the rotor during starting, a locking pin secured to the crank case and extending through a slot in said mounting plate to a position adjacent the rotor, means on said rotor adapted to engage said pin during cranking of the engine for locking the rotor against turning with the shaft, means for releasing said locking means, and means for adjustably rotating said mounting plate relative to the engine to effect adjustment in the timing of the ignition.

ELMER. C. KIEKHAEFER.

REFERENCES CITED UNITED STATES PATENTS Name Date Dunham Jan. 17, 1939 Number 

